Diffusion transfer film unit with improved dye image receiving layer comprising a basic polymeric mordant

ABSTRACT

A HYDROPHILIC COLLOIDAL OVERCOAT LAYER ON A DYE IMAGERECEIVING ELEMENT IS USEFUL FOR PROVIDING STABLE DYE IMAGES OF HIGH QUALITY IN A COLOR DEVELOPMENT DIFFUSION TRANSFER SYSTEM UTILIZING IMMOBILE COUPLER WHICH FORM DIFFUSIBLE DYES.

UnitdStates Patent C 3,698,896 DIFFUSION TRANSFER FILM UNIT WITH IM- PROVED DYE IMAGE RECEIVING LAYER COMPRISING A BASIC POLYIVLERIC MORDANT Thomas 1. Abbott, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y. No Drawing. Filed Dec. 21, 1970, Ser. No. 100,486 Int. Cl. G03c 5/54, 5/48, 1/48 US. Cl. 963 22 Claims ABSTRACT OF THE DISCLOSURE A hydrophilic colloidal overcoat layer on a dye imagereceiving element is useful for providing stable dye images of high quality in a color development diffusion transfer system utilizing immobile couplers which form difiusible dyes.

This invention relates to the art of photography and more particularly to color diffusion transfer film units and methods for obtaining stable, positive, right-reading diffusion transfer dye images of high quality.

US. Pat. 3,227,550 of Whitmore and Mader issued Jan. 4, 1966 and US. Pat. 3,227,552 of Whitmore issued Jan. 4, 1966 describe photographic image transfer processes wherein an immobile coupler is reacted with oxidized color developer to form a mobile dye which is transferred by diffusion to a receiving layer to form a color image. During the development phase of the color development diffusion transfer process,,the image dyes formed in the respective blue, green and red-sensitive silver halide emulsion layers diffuse into an image-receiving layer of the receiving element Where the dyes are mordanted to form the transferred image. At the same time, small amounts of development reaction products and unused color developer diffuse into the image-receiving layer. When the receiving element is separated from the photosensitive element, oxygen in the atmosphere causes rapid oxidation of the unused developer, self-coupling of the developer occurs, thereby producing a yellowish-brown stain, particularly in the highlight or minimum density areas.

US. Pat. 3,445,228 issued May 20, 1969 of Beavers et al. discloses that a white pigment contained in an interlayer of a dye image-receiving element for use in the above-described process conceals the stain formed in an acid layer and functions also as a timing layer. It would be desirable to provide an image-receiving element wherein acid layers and pigment layers are not required and wherein higher maximum dye densities are obtainable as well as a reduction of visible stain and background densities.

US. Pat. 3,295,970, issued Jan. 3, 1967 of Rogers dis closes that an overcoat of polyvinyl alcohol on a particular image-receiving element employed in a dye developer diffusion transfer system improves the light stability of the transferred image. There is no teaching in this patent, however, of other color diffusion transfer systems such as those employing couplers and color developing agents and the particular dye image-receiving materials required therefor.

Accordingly, it is an object of this invention to provide a film unit employing an image-receiving element capable of receiving stable dye images of high quality.

It is another object of this invention to provide a proc: ess for producing a transfer image wherein the receiving element does not require a post-processing washing step.

It is another object of this invention to provide a film unit employing an image-receiving element having greater dye receptivity, thereby providing higher dye densities of the transferred image.

Patented Oct. 17, 1972 It is another object of this invention to provide a film unit employing an image-receiving element more resistant to oxidized color developer stain, thereby reducing the minimum or background densities.

These and other objects are achieved by a photographic film unit according to my invention, which is adapted to be processed by passing the unit between a pair of juxtaposed pressure-applying members, such as would be found in a camera designed for in-camera processing, comprising:

(a) a photosensitive element comprising a support having thereon at least one, and preferably three, photosensitive silver halide emulsion layers, each silver halide emulsion layer having associated therewith a dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible dye;

(b) a dye image-receiving element comprising a support having thereon a dye image-receiving layer comprising a basic polymeric mordant and a hydrophilic colloid layer; and

(c) a rupturable container containing an alkaline processing composition and which is adapted to be positioned between said photosensitive element and said dye image-receiving element during processing of said film unit so that a compressive force applied to the container by pressure-applying members in a camera will effect a discharge of the containers contents between the image-receiving element and the outermost layer of the photosensitive element,

the film unit containing an aromatic, primary amino color developing agent, preferably in the rupturable container.

The dye image-receiving layer of my film unit is located on a separate support which is adapted to be superposed on the photosensitive element after exposure thereof. Upon rupturing the pod, the processing composition dif fuses through the film unit thereby initiating imagewise development of the silver halide emulsion layers. Dye images formed as a result of the reaction of oxidized developer with nondiifusible couplers contained in each silver halide emulsion layer or in a layer contiguous thereto, are formed as a function of the imagewise exposure of each said silver halide emulsion layer. At least a portion of the imagewise distributions of diifusible dye diffuses to the image-receiving layer. A positive dye image is viewable upon separation of the image-receiving element from the negative element. The colloid overcoat layer on the dye image-receiving element enhances the maximum density and keeping stability while reducing the minimum density of the transferred dye image.

A number of hydrophilic colloids can be employed as dye image-receiving element overcoats in the practice of the invention, e.g., gelatin, casein, starch, dextran, polyvinyl pyrrolidone, gum arabic, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, guargum, gum acacia, e'tc. Gelatin and casein are preferred.

The hydrophilic colloid overcoat layer for the dye image-receiving element used in my invention can be employed in any coverage suitable for the intended purpose. Generally, 20-100 mg. per square foot of receiver element can be employed with effective results with a preferred coverage being 30-60 mg. per square foot.

The hydrophilic colloidal overcoat on the image-receiving element can also contain ultraviolet absorbing materials to protect the mordanted dye images from fading due to ultraviolet light such as those described in U.S-. Pats. 3,460,942; 3,069,262; 3,330,680; and 3,330,656. Brightening agents such as the stilbenes, coumarins, triazines, oxazoles, etc. can be included in the receiving element, if desired. Best results are obtained if the brightening agent is in a layer under the image-receiving layer.

The film assembly of my invention can be used to produce positive images in single or multicolors. In a threecolor system, each silver halide emulsion layer of the film assembly of my invention will have associated therewith a dye image-providing material possessing a spectral absorption range substantially complementary to the predominant sensitivity range of its associated emulsion, i.e., the blue-sensitive silver halide emulsion layer wil lhave a yellow dye image-providing material associated therewith, the green-sensitive silver halide emulsion layer will have a magenta dye image-providing material associated therewith, and the red-sensitive silver halide emulsion layer will have a cyan dye image-providing material associated therewith. The dye image-providing material associated with each silver halide emulsion layer can be contained either in the silver halide emulsion layer itself or in a layer contiguous to the silver halide emulsion layer.

Spectral sensitizing dyes can be used conveniently to confer additional sensitivity to the light sensitive halide emulsion of the multilayer photographic elements of the invention. 'For instance, additional spectral sensitization can be obtained by treating the emulsion with a solution of a sensitizing dye in an organic solvent or the dye may be added in the form of a dispersion as described in Owens et al. British Pat. 1,154,781. For optimum results, the dye can either be added to the emulsion as a final step or at some earlier stage.

Sensitizing dyes useful in sensitizing such emulsions are described, for example, in Brooker et al. U.S. Pat. 2,526,- 632, issued Oct. 24, 1950; Sprague U.S. Pat. 2,503,776, issued Apr. 11, 1950; Brooker et al. U.S. Pat. 2,493,748; and Taber et al. U.S. Pat. 3,384,486. Spectral sensitizers which can be used include the cyanines, merocyanines, complex (tri or tetranuclear) merocyanines, complex (tri or tetranuclear) cyanines, holopolar cyanines, styryls, hemicyanines (e.g., enamine hemicyanines), oxonols and hemioxonols. Dyes of the cyanine classes can contain such basic nuclei as the thiazolines, oxazolines, pyrrolines, pyridines, oxazoles, thiazoles, selenazoles and imidazoles. Such nuclei can contain alkyl, alkylene, hydroxyalkyl, sulfoalkyl, carboxyalkyl, aminoalkyl and enamine groups and can be fused to carbocyclic or heterocyclic ring systems either unsubstituted or substituted with halogen, phenyl, alky, haloalkyl, cyano, or alkoxy groups. The dyes can be symmetrical or unsymmetrical and can contain alkyl, phenyl, enamine or heterocyclic substituents on the methine or polymethine chain. The merocyanine dyes can contain the basic nuclei mentioned above as well as acid nuclei such as thiohydantoins, rhodanines, oxazolidenediones, thiazolidenediones, barbituric acids, thiazolineones, and malononitrile. These acid nuclei can be substituted with alkyl, alkylene, phenyl, carboxyalkyl, sulfoalkyl, hydroxyalkyl, alkoxyalkyl, alkylamino groups, or heterocyclic nuclei. Combinations of these dyes can be used, if desired. In addition, supersensitizing addenda which do not absorb visible light can be included, for instance, ascorbic acid derivatives, azaindenes, cadmium salts, and organic sulfonic acids as described in McFall et al. U.S. Pat. 2,933,390 and Jones et a1. U.S. Pat. 2,937,- 089.

The various silver halide emulsion layers of a color film assembly of the invention can be disposed in the usual order, i.e., the blue-sensitive silver halide emulsion layer first with respect to the exposure side, followed by the green-sensitive and red-sensitive silver halide emulsion layers. If desired, a yellow dye layer or a Carey Lea silver layer can be present between the blue-sensitive and greensensitive silver halide emulsion layers for absorbing or filtering blue radiation that may be transmitted through the blue-sensitive layer. If desired, the selectively sensitized silver halide emulson layers can be disposed in a different order, e.g., the blue-sensitive layer first with respect to the exposure side, followed by the red-sensitive and green-sensitive layers.

The silver halide emulsions used in this invention can comprise, for example, silver chloride, silver bromide, silver chlorobromide, silver bromoiodide, silver chlorobromoiodide or mixtures thereof. The emulsions can be coarse or fine grain and can be prepared by any of the well-known procedures, e.g., single jet emulsions, double jet emulsions, such as Lippmann emulsions, ammoni-acal emulsions, thiocyanate or thioether ripened emulsions such as those described in Nietz et al. U.S. Pat. 2,222,264; Illingsworth U.S. Pat. 3,320,069; and McBride U.S. Pat. 3,271,157. Emulsions that contain silver halide grains having substantial surface sensitivity can be used, and emulsions that contain silver halide grains having substantial sensitivity inside the grains can be used such as those described in Davey et al. U.S. Pat. 2,592,250; Porter et al. U.S. Pat. 3,206,313; and Bacon et al. U.S. Pat. 3,- 447,927. The emulsions can be regular grain emulsions such as the type described in Klein and Moisar, J. Phot. Sci., vol. 12, No. 5, September/October 1964, pp. 242- 251. Negative-type emulsions can be used or direct positive emulsions can be used such as those described in Leermakers U.S. Pat. 2,184,013; Kendall et al. U.S. Pat. 2,541,472; Berriman U.S. Pat. 3,367,778; Schouwenaars British Pat. 723,019; Illingsworth et al. French Pat. 1,520,- 821; Ives U.S. -Pat. 2,563,785; Knott et a1. U.S. Pat. 2,456,953 and Land U.S. Pat. 2,861,885.

The emulsions used in this invention can be sensitized with chemical sensitizers, such as with reducing agents; sulfur, selenium or tellurium compounds; gold, platinum or palladium compounds; or combinations of these. Suitable procedures are described in Sheppard et al. U.S. Pat. 1,623,499; Waller et 'al. U.S. Pat. 2,399,083; McVeigh U.S. Pat. 3,297,447; and Dunn U.S. Pat. 3,297,446.

The silver halide emulsions used in this invention may contain speed increasing compounds such as polyalkylene glycols, cationic surface active agents and thioethers or combinations of these as described in Piper U.S. Pat. 2,886,437; Dann et .al. U.S. Pat. 3,046,134; Carroll et al. U.S. Pat. 2,944,900; and Gofi'e U.S. Pat. 3,294,540.

The silver halide emulsions used in the practice of this invention can be protected against the production of fog and can be stabilized against loss of sensitivity during keeping. Suitable antifoggants and stabilizers each used alone or in combination include thiazolium salts described in Brooker et al. U.S. Pat. 2,131,038 and Allen et al. U.S. Pat. 2,694,716; the azaindenes described in Piper U.S. Pat. 2,886,437 and Heimbach et al. U.S. Pat. 2,444,605; the mercury salts as described in Allen et al. U.S. Pat. 2,728,663; the urazoles described in Anderson et al. US. Pat. 3,287,135; the sulfocatechols described in Kennard et al. U.S. Pat. 3,236,652; the oximes described in Carroll et al. British Pat. 623,448; nitron; nitroindazoles; the mercaptotetrazoles described in Kendall et al. U.S. Pat. 2,403,927; Kennard et al. U.S. Pat. 3,266,897 and Luckey et al. U.S. Pat. 3,397,987; the polyvalent metal salts described in Jones U.S. Pat. 2,839,405; the thiuronium salts described in Herz et al. U.S. Pat. 3,220,839; and the palladium, platinum and gold salts described in Trivelli et al. U.S. Pat. 2,566,263 and Yutzy et al. U.S. Pat. 2,597,915.

The nondiffusible couplers employed in this invention include those having the formulas:

DY ELINK---(COUP-BALL) and BALLLINK(COUPSOL) wherein (l) DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing radical; (2) LINK is a connecting radical such as an azo radical,

a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical or an azoxy radical;

(3) COUP is a coupler radical such as a -pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical or an open-chain ketomethylene coupler radical, COUP being substituted in the coupling position with LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render such coupler nondiifusible during development in the alkaline processing composition;

(5) SOL is a hydrogen atom or an acidic solubilizing group when the color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when the color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of 1 to 2 when LINK is an alkylidene radical, and n is 1 when LINK is an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical or an azoxy radical.

The acidic solubilizing radicals attached to the difiusible dye producing couplers described above can be solubilizing radicals which when attached to the coupler or developer moieties of the dyes, render the dyes diffusible in alkaline processing compositions. Typical of such radicals are carboxylic, sulfonic, ionizable sulfonamide, and hydroxy-substituted groups that lend to dyes negative charges.

The nature of the ballast groups in the diifusible dyeproducing coupler compounds described above (BALL) is not critical as long as they confer nonditfusibility to the coupler compounds. Typical ballast groups include long chain alkyl radicals linked directly or indirectly to the coupler molecules as well as aromatic radicals of the henzene and naphthalene series, etc., linked directly or indirectly to the coupler molecules by a splittable linkage,

or by a removable or irremovable but otherwise nonfunctional linkage depending upon the nature of the coupler compound. Useful ballast groups have at least 8 carbon atoms.

Typical dye radical sub'stituents (DYE-) include azo, azomethine, indoaniline, indophenol, anthraquinone and related dye radicals well known in the art that exhibit selective absorption in the visible spectrum. The dye radicals contain acidic solubilizing moieties.

With regard to the above-described coupler radicals (COUP), the coupling position is well known to those skilled in the photographic art. The S-pyrazolone coupler radicals couple at the carbon atom in the 4-position, the phenolic coupler radicals, including a-naphthols, couple at the carbon atom in the 4-position and the openchain ketomethylene coupler radicals couple to the carbon atom forming the methylene moiety (e.g.,

* denoting the coupling position), Pyrazolotriazole couplers and their coupling position are described, for example, in U.S. P'at. 3,061,432 and US. application Ser. No. 778,329 of Bailey et al., filed Nov. 22, 1968, and now abandoned.

Particularly good results are obtained When the cyanproducing coupler has the formula BALLOCYAN- COUP, the magenta-producing coupler has the formula BALL-N=N-MAGCOUP and the yellow-producing coupler has the formula BALLOYELLCOUP where- (a) BALL is a photographically inert organic ballasting radical having at least 8 carbon atoms and of such molecular size and configuration as to render the coupler nondiffusible during development in an alkaline processing composition;

(b) CYANCOUP is a phenolic coupler radical substituted in the 2-position with a fully substituted amido group and attached to the O moiety of the cyan-producing coupler in the coupling position;

(0) MAGCOUP is a S-pyrazolone coupler radical joined to the -N N moiety of the magenta-producing coupler in the coupling position; and

(d) YEIJLCOUP is an open-chain ketomethylene coupler radical attached to the --O' moiety of the yellowproducing coupler in the coupling position.

The term nondiifusing used herein as applied to the couplers, has the meaning commonly applied to the term in color photography and denotes materials which for all practical purposes do not migrate or wander through organic colloid layers, such as gelatin, comprising the sensitive elements of the invention. The same meaning is to be attached to the term immobile.

The term diffusible as applied to the dyes formed from the nondiifusing couplers in this invention has the converse meaning and denotes materials having the property of diffusing effectively through the colloid layers of the sensitive elements in the presence of the nondifiusing materials from which they are derived. Mobile has the same meaning.

When the couplers having the formula DYELINK (COUPBALL) as described above are reacted with oxidized color developing agent, the connecting radical (LINK) is split and a diifusible preformed dye (DYE) is released which diffuses imagewise to a reception layer. An acidic solubilizing group on the preformed dye lends diffusibility to the dye molecule. The coupling portion of the coupler (CO'UP) couples with the color developing agent oxidation product to form a dye that is nondiffusible because of the attached ballasting group (BALL) in a noncoupling position. In this type of coupler, the color of the diffusible dye is determined by the color of the preformed dye moiety (DYE), the color of the reaction product of color developer oxidation product and the coupler moiety (COUP) being unimportant to the color of the diifusible image.

When couplers having the formula BALLLINK (COUPSOL) as described above are reacted with oxidized color developing agent, the connecting radical (LINK) is split and a diffusible dye is formed with the color developing agent oxidation product and the coupling portion (COUP) of the coupler which diffuses imagewise to a reception layer. Diifusibility is imparted to the dye by an acidic solubilizing group attached to a noncoupling position of the coupling portion (COUP') of the coupler or to the color developing agent. The ballasting portion of the coupler remains immobile. In this type of coupler, the color of the dilfusible dye is determined by the color of the reaction product of color developer oxidation product and the coupler moiety (COiU-P).

In using both types of couplers in the invention, the production of diifusible dye images is a function of the reduction of developable silver halide images which may involve direct or reversal development of the silver halide emulsions with an aromatic primary amino developing agent. If the silver halide emulsion employed is a direct positive silver halide emulsion, such as an internal image emulsion or a solarizing emulsion, which is developable in unexposed areas, a positive image can be obtained in the receiver portion of the film unit. In this embodiment, the nondiffusible coupler can be located in the silver halide emulsion itself. After exposure of the film unit, the alkaline processing composition permeates the various layers to initiate development of the exposed photosensitive silver halide emulsion layers. The aromatic primary amino color developing agent present in the film unit develops each of the silver halide emulsion layers in the unexposed areas (since the silver halide emulsions are direct positive ones), thus causing the developing agent to become oxidized imagewise corresponding to the unexposed areas of the direct positive silver halide emulsion layers. The oxidized developing agent then reacts with the nondilfusible coupler present in each silver halide emulsion layer to form imagewise distributions, respectively, of diffusible cyan, magenta and yellow dye as a function of the imagewise exposure of each of the silver halide emulsion layers. At least a portion of the imagewise distributions of dilfusible cyan, magenta and yellow dye diffuse to the image-receiving layer to provide a positive dye image upon separation of the receiver from the negative. Specific examples of such nondiffusing couplers and other details concerning this type of photographic chemistry are found in US. Pats. 3,227,550 and 3,227,552.

Internal image silver halide emulsions useful in the above-described embodiment are direct positive emulsions that form latent images predominantly inside the silver halide grains, as distinguished from silver halide grains that form latent images predominantly on the surface thereof. Such internal image emulsions were described by Davey et al. in US. Pat. 2,592,250 issued Apr. 8, 1952, and elsewhere in the literature. Internal image silver halide emulsions can be defined in terms of the increased maximum density obtained when developed with internal-type developers over that obtained when developed with surface-type developers. Suitable internal image emulsions are those which, when measured according to normal photographic techniques by coating a test portion of the silver halide emulsion on a transparent support, exposing to a light intensity scale having a fixed time between 0.01 and 1 second, and developing for 3 minutes at 20 C. in Developer A below (internal-type developer), have a maximum density at least five times the maximum density obtained when an equally exposed silver halide emulsion is developed for 4 minutes at 20 C. in Developer B described below (surface-type developer).

DEVELOPER A G. Hydroquinone 15 Monomethyl-p-aminophenol sulfate 15 Sodium sulfite (desiccated) 50 Potassium bromide Sodium hydroxide 25 Sodium thiosulfate 20 Water to make one liter.

DEVELOPER B G. P-hydroxyphenylglycine 10 Sodium carbonate 100 Water to make one liter.

The solarizing direct positive silver halide emulsions useful in the above-described embodiment are well known silver halide emulsions which have been effectively fogged either chemically or by radiation to a point which corresponds approximately to the maximum density of the reversal curve as shown by Mees, The Theory of the Photographic Process, published by the Macmillan Co., New York, N.Y., 1942, pages 261-297. Typical methods for the preparation of solarizing emulsions are shown by Groves British Pat. 443,245, Feb. 25, 1936, who subjected emulsions to Roentgen rays until an emulsion layer formed therefrom, when developed without preliminary exposure, is blackened up to the apex of its graduation curve; Szaz British Pat. 462,730, Mar. 15, 1937, the use of either light or chemicals such as silver nitrate, organic sulfur compounds and dyes to convert ordinary silver halide emulsions to solarizing direct positive emulsions; and Arens US. Pat. 2,005,837, June 25, 1935, the use of silver nitrate and other compounds in conjunction with heat to effect solarization. Kendall and Hill US. Pat. 2,541,472, Feb. 13, 1951, shows useful solarized emulsions particularly susceptible to exposure with long wavelength light and initial development to produce the Herschel effect described by Mees above, produced by adding benzothiazoles and other compounds to the emulsions which are fogged either chemically or with white light. In using the emulsions a suflicient reversal image exposure is employed using minus blue light of from about 500- 700 Ill .0 wavelength preferably 520-554 Ill 1., to substantially destroy the latent image in the silver halide grains in the region of the image exposure. Particularly useful are the fogged direct positive emulsions of Berriman US. Pat. 3,367,778 and French Pat. 1,520,821.

Internal image silver halide emulsions which contain or which are processed in the presence of fogging or nucleating agents are particularly useful in the above-described embodiment employing nondiffusible couplers since the use of fogging agents is a convenient way to inject electrons into the silver halide grains. Suitable fogging, agents include the hydrazines disclosed in Ives U.S. Pats. 2,588,- 982 issued Mar. 11, 1952 and 2,563,785 issued Aug. 7, 1951; the hydrazides and hydrazones disclosed in Whitmore US. Pat. 3,227,552 issued Jan. 4, 1966; hydrazone quaternary salts described in Lincoln and Heseltine application Ser. No. 828,064 filed Apr. 28, 1969, now abandoned; or mixtures thereof. The quantity of fogging agent employed can be widely varied depending upon the results desired. Generally, the concentration of fogging agent is from about 1 to about 20 mg. per square foot of photosensitive layer in the photosensitive element or from about 0.1 to about 2 grams per liter of developer if it is located in the developer.

Other embodiments of my invention employ the photosensitive elements described in the above-mentioned U.S. Pats. 3,227,550; 3,227,551 and 3,227,552 and in British Pat. 904,364, page 19, lines 1-41. These embodiments all employ the nondilfusible couplers described above.

In the above-described embodiments employing nondiifusible couplers, interlayers are generally employed between the various photosensitive color-forming units to scavenge oxidized developing agent and prevent it from forming an unwanted dye in another color-forming unit. Such interlayers would generally comprise a hydrophilic polymer such as gelatin and an immobilizing coupler, which is capable of reacting with oxidized aromatic primary amino color developing agent to form an immobile product.

As previously mentioned, the aromatic primary amino color developing agent employed in the above-described embodiments is preferably present in the alkaline processing composition in the rupturable pod. The color developing agent can also be incorporated into the negative portion of the film unit as a separate layer, e.g., by employing a Schiif base derivative of an aromatic primary amino color developing agent such as that formed b reacting o-sulfobenzaldehyde and N,N-diethyl-3-methyl-4- aminoaniline. Such incorporated developing agent will be activated by the alkaline processing composition. While the incorporated developing agent can be positioned in any layer of the photosensitive element from which it can be readily made available for development upon activation with alkaline processing composition, it is generally either incorporated in the light-sensitive silver halide emulsion layers or in layers contiguous thereto. As mentioned above, aromatic primary amino color developing agents employed in this invention are preferably p-phenylenediamine developing agents, These developing agents are well known to those skilled in the art and include 4-amino-N,N-diethyl-3-methylaniline hydrochloride, N,N-diethyl-p-phenylenediamine, Z-amino-S-diethylamino toluene, N-ethyl-B-methane-sulfonamido-ethyl-3-methyl-4-aminoaniline, 4-amino-N-ethyl-3-methyl-N-(fl-sulfoethyl)aniline, 4-amino-N-ethyl-3 -methoxy-N- (B-sulfoethyl) aniline, 4-amino-N-ethyl-N- (B-hydroxyethyl) aniline, 4-amino-N,N-diethyl-3-hydroxymethyl aniline, 4-amino-N-methyl-N- (fl-carboxyethyl) aniline, 4-amino-N,N-bisfi-hydroxyethyl) aniline,

4-amino-N,N-bis(fi-hydroxyethyl)-3-methyl aniline,

3 -acetamido-4-amino -N,N-bis (p-hydroxyethyl) aniline,

4- amino-N-ethyl-N- 2,3 -dihydroxypropyl) -3-methyl aniline sulfate salt,

4-amino-N,N-diethyl-3-(3-hydroxypropoxy)-aniline,

and the like.

The rupturable container employed in this invention can be of the type disclosed in U. S. Pats. Nos. 2,543,181; 2,634,886; 2,653,732; 2,723,051; 3,056,492; 3,056,491 and 3,152,515. In general, such containers comprise a rectangular sheet of fluid and air-impervious material folded longitudinally upon itself to form two walls which are sealed to one another along their longitudinal and end margins to form a cavity in which the processing composition is contained.

In a color film unit according to the invention, each silver halide emulsion layer containing a dye image-providing material or having the dye image-providing material present in a contiguous layer may be separated from the other silver halide emulsion layers in the negative portion of the film unit by materials in addition to those described above, including gelatin, calcium alginate, or any of those disclosed in U.S. Pat. No. 3,384,483, polymeric materials such as polyvinylamides as disclosed in US. Pat. 3,421,892, or any of those disclosed in US. Pats. Nos. 2,992,104; 3,043,692; 3,044,873; 3,061,428; 3,069,263; 3,069,264; 3,121,011; and 3,427,158.

Generally speaking, except where noted otherwise, the silver halide emulsion layers in the invention comprise photosensitive silver halide dispersed in gelatin and are about 0.6 to 6 microns in thickness; the dye image-providing materials are dispersed in an aqueous alkaline solution-permeable polymeric binder, such as gelatin, as a separate layer about 1 to 7 microns in thickness; and the alkaline solution-permeable polymeric interlayers, e.g., gelatin, are about 1 to microns in thickness. Of course, these thicknesses are approximate only and can be modified according to the product desired. In addition to gelatin, other suitable hydrophilic materials include both naturally-occurring substances such as proteins, cellulose derivatives, polysaccharides such as dextran, gum arabic and the like; and synthetic polymeric substances such as water soluble polyvinyl compounds like poly(vinylpyrrolidone), acrylamide polymers and the like.

The photographic emulsion layers and other layers of a photographic element employed in the practice of this invention can also contain alone or in combination with hydrophilic, water-permeable colloids, other synthetic polymeric compounds such as dispersed vinyl compounds such as in latex form and particularly those which increase the dimensional stability of the photographic materials. Suitable synthetic polymers include those described, for example, in Nottorf US. Pat. 3,142,568, issued July 28, 1964; White US. Pat. 3,193,386, issued July 6, 1965; Houck et al. US. Pat. 3,062,674, issued Nov. 6, 1962; Houck et al. US. Pat. 3,220,844, issued Nov. 30, 1965; Ream et al. US. Pat. 3,287,289, issued Nov. 22, 1966; and Dykstra US. Pat. 3,411,911, issued Nov. 19, 1968. Particularly efiective are water-insoluble polymers of alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates, those which have cross-linking sites which facilitate hardening or curing, and those having recurring sulfobetaine units as described in Dykstra Canadian Pat. 774,054.

As described above, the dye image-receiving layer in this invention comprises a basic polymeric mordant. Especially preferred basic polymeric mordants are those described and claimed in copending application Ser. No. 709,812, filed Mar. 1, 1968, now abandoned, of my co workers Cohen, King and Minsk and their continuationin-part applications Ser. Nos. 100,487 and 100,491 filed Dec. 21, 1970. The basic polymeric mordants are composed of a polymer having quaternary nitrogen groups and at least two aromatic nuclei for each quaternary nitrogen atom, said polymeric compound being substantially 10 free of carboxy groups. In addition, the basic polymeric mordants described in Cohen et al. US. Pat. 3,488,706, issued Jan. 6, 1970 can also be employed with good results.

Preferred basic polymeric mordants comprise units of the following formula in copolymerized relationship with units of at least one other ethylenically unsaturated monomer:

wherein R and R can each be hydrogen atoms, lower alkyl, e.g., 1-6 carbon atoms such as methyl, ethyl, propyl, n-butyl, t-butyl, and the like; and R can additionally be a group containing at least one aromatic nucleus including substituted aryl, e-.g., phenyl, naphthyl, tolyl, etc.; Q can be a covalent bond, a divalent alkylene, arylene, aralkylene or arylenealkylene radical such as or other radicals including o NHR where R is an alkylene radical typically having 1-4 carbon atoms or R can be taken together with Q to form a or 4-pyridinium and X is an anion, i.e., a monovalent negative-salt form ing radical or atom in ionic relationship with the positive salt-forming radical or polymer cation such as a halide, alkyl, sulfate, sulfonate, for example, such as p-toluenesulfonate, dialkyl phosphate, and the like; wherein said polymer is substantially free of carboxy groups. Preferably, the positive salt forming radical of said polymer comprises at least two aromatic nuclei for each quaternary nitrogen atom in said polymer.

The above-described basic polymeric mordants are water-soluble polymers having a polyhydrocarbon back- 11 bone and are composed of recurring units supplying quaternized nitrogen atoms and preferably having at least two aromatic nuclei, such as aryl groups, per quaternized nitrogen atom. The polymers should be substantially free of carboxy groups for the presence of carboxy groups in the interpolymers interferes with effective dye mordanting.

The above-described basic polymer mordants are generally prepared by quaternizing an intermediate polymer having tertiary nitrogen atoms with an alkylating or aralkylation agent. The method of preparation of the intermediate polymer containing the tertiary nitrogen atoms for subsequent quaternization is not critical. Any of the methods known in the art such as mass, solution, or bead polymerization, as well as condensation polymerization, can be used, and the catalyst known to the art such as ultraviolet light, peroxides, azo compounds, e.g., azobisisobutyronitrile, etc. can be employed.

The mordanting amount of basic polymeric mordant to be employed in a dye image-receiving layer will vary over a wide range depending upon the amount of dye to be mordanted, the particular polymer employed, the imaging chemistry involved, etc. This amount can easily be determined by one skilled in the art.

Typical ethylenically unsaturated monomers which can be used to form ethenic interpolymers comprising the above-described basic polymeric mordants include ethylene, propylene, l-butene, isobutene, 2-methylpentene, 2- methylbutene, 1,1,4,4 tetramethylbutadiene, styrene, alpha-methylstyrene; monoethylenically unsaturated esters of aliphatic acids such as vinyl acetate, isopropenyl acetate, allyl acetate, etc.; esters of ethylenically unsaturated monoor dicarboxylic acids such as methyl acrylate, methyl methacrylate, ethyl acrylate, diethyl methylene malonate, etc.; monoethylenically unsaturated compounds such as acrylonitrile, allyl cyanide, and dienes such as butadiene and isoprene.

For further details concerning the above-described basic polymeric mordants and their preparation, reference is made to the above-mentioned US. Pat. 3,488,706 and US. application Ser. No. 709,812, filed Mar. 1, 1968 of Cohen, King and Minsk and the continuation-in-part applications Ser. Nos. 100,487 and 100,491 filed Dec. 21,

Basic polymeric mordants included with in the scope of the invention include the following:

Copoly [styrene-N,N-dimethyl-N-ethoxycarbonylmethyl- N- 3-maleimidopropyl ammonium chloride] Copoly [styrene-N,N-dimethyl-N-cyanomethyl-N- (3-maleimidopropyl) ammonium chloride] Copoly [styreneN,N-dimethyl-N-methoxymethyl- N- 3-maleimidopropyl) ammonium chloride] Copoly [styreneN,N,N-trimethyl-N- 3 -maleimidopropyl)-ammonium p-toluenesulfonate];

Copoly [styrene-N-benzyl-N,N-dimethyl-N- 3- maleimidopropyl ammonium chloride] Copoly[styrene-N-(3-acrylamidopropyl) -N,N-dimethyl- N-4-nitrobenzylammonium chloride];

Copoly [styreneN 3-acrylamidopropyl -N,N-dimethyl- N- l-naphthylmethyl) ammonium chloride] Copoly[styreneN-(3-acrylamidopropyl) N-'benzyl- N,N-dimethylammonium chloride];

Copoly [styrene--N- 3-maleimidopropyl) -N,N-dimethyl- N- 4-phenylbenzyl ammonium chloride] Copoly styrene-N- (Z-methacryloyloxyethyl -N,N-

dimethyl-N-benzylammonium chloride];

Copoly(styrene1-benzyl-2-methyl-5-vinylpyridinium chloride) Copoly [2-vinylpyridine2-vinyl-N-( l-naphthylmethyl) pyridinium chloride] Copoly [N-acrylamidopropyl-N,N-dimethyl-N-vinyloxycarbomethylammonium chlorideNbenzyl-N,N- dimethyl-N-vinyloxycarbomethylammonium chloride];

Copoly 2-vinylnaphthaleneN-( l-naphthylmethyl -N,N-

dimethyl-N-maleimidopropylammonium chloride]; and

Cop0ly[styreneN-(3-acrylamidopropyl) -N-carbamoylmethyl-N,N-dimethylammonium chloride].

Use of a pH-lowering layer in the dye image-receiving element employed in this invention will increase the stability of the transferred image. Generally, the pH-lowering layer will effect a reduction in the pH of the image layer from about 13 or 14 to at least 11 and preferably 5-8 within a short time after imbibition. For example, polymeric acids as disclosed in US. Pat. 3,362,819 may be employed. Such polymeric acids reduce the pH of the film unit after development to terminate further dye transfer and thus stabilize the dye image. Such polymeric acids comprise polymers containing acid groups, such as carboxylic acid and sulfonic acid groups, which are capable of forming salts with alkali metals, such as sodium or potassium, or with organic bases, particularly quaternary ammonium bases, such as tetramethyl ammonium hydroxide. The polymers can also contain potentially acid-yielding groups such as anhydrides or lactones or other groups which are capable of reacting with bases to capture and retain them. Generally the most useful polymeric acids contain free carboxyl groups, being insoluble in water in the free acid form and which form water-soluble sodium and/or potassium salts. Examples of such polymeric acids include dibasic acid half-ester derivatives of cellulose which derivatives contain free carboxyl groups, e.g., cellulose acetate hydrogen phthalate, cellulose acetate hydrogen glutarate, cellulose acetate hydrogen succinate, ethyl cellulose hydrogen succinate, ethyl cellulose acetate hydrogen succinate, cellulose acetate succinate hydrogen phthalate; ether and ester derivatives of cellulose modified with sulfoanhydrides, e.g., with ortho-sulfobenzoic anhydride; polystyrene sulfonic acid; carboxymethyl cellulose; polyvinyl hydrogen phthalate; polyvinyl acetate hydrogen phthalate; polyacrylic acid, acetals of polyvinyl alcohol with carboxy or sulfo substituted aldehydes, e.g., 0-, mor p-benzaldehyde sulfonic acid or carboxylic acid; partial esters of ethylene/ maleic anhydride copolymers; partial esters of methylvinyl ether/maleic anhydride copolymers; etc. In addition, solid monomeric acid materials could also be used such as palmitic acid, oxalic acid, se'bacic acid, hydrocinnamic acid, metanilic acid, paratoluenesulfonic acid and benzenedisulfonic acid. Other suitable materials are disclosed in US. Pat. Nos. 3,422,075 and 2,635,048.

The pH-lowering layer is usually about 0.3 to about 1.5 mils in thickness and is preferably located in the dye image-receiving element between the support and the dye image-receiving layer.

An inert timing or spacer layer coated over the pH- lowering layer may also be used to time or control the pH reduction of the dye image-receiving element as a function of the rate at which the alkali diffuses through the inert spacer layer. Examples of such timing layers include gelatin, polyvinyl alcohol or any of those disclosed in US. Pat. 3,455,686. The timing layer is also effective in evening out the various reaction rates over a wide range of temperatures, e.g., premature pH reduction is prevented when irnbibition is effected at temperatures above room temperature, for example, at to F. The timing layer is usually about 0.1 to about 0.7 mil in thickness and may contain a light-reflective material, such as titanium dioxide, if desired. Especially good results are obtained when the timing layer comprises a hydrolyzable polymer or a mixture of such polymers which are slowly hydrolyzed by the processing composition. Examples of such hydrolyza'ble polymers include polyvinyl alcohol, polyvinyl acetate, polyamides, polyvinyl ethers, partial acetals of polyvinyl alcohol, etc.

The alkaline processing composition employed in this invention is the conventional aqueous solution of an alkaline material, e.g., sodium hydroxide, sodium carbonate or an amine such as diethylamine, preferably possessing a pH in excess of 12. The solution also preferably contains a viscosity-increasing compound such as a high molecular weight polymer, e.g., a water-soluble ether inert to alkaline solutions such as hydroxyethyl cellulose or alkali metal salts of carboxymethyl cellulose such as sodium carboxymethyl cellulose. A concentration of viscosity-increasing compound of about 1 to about 5% by weight of the processing solution is preferred which will impart thereto a viscosity of about 100 cps. to about 200,000 cps.

While the alkaline processing composition used in this invention can be employed in a rupturable container, as described previously, other methods of applying processing composition could also be employed, e.g., bathing the photosensitive element in a processing bath.

While the film units of my invention can be modified so as to be employed in roll form, they are preferably used in cartridges similar to those described in U.S. Pats. 3,080,805; 3,161,118; and 3,161,122; said patents also illustrating typical cameras for performing color diffusion transfer processes of my invention.

The supports for the photographic elements of this invention can be any material as long as it does not deleteriously affect the photographic properties of the film unit and is dimensionally stable. Typical materials include cellulose nitrate film, cellulose acetate film, poly(vinyl acetal) film, polystyrene film, poly(ethyleneterephthalate) film, polycarbonate film, poly-a-olefins such as polyethylene and polypropylene film, and related films or resinous materials as well as glass.

While the invention has been described with reference to layers of silver halide emulsions and dye image-providing materials, dotwise coating, such as would be obtained using a gravure printing technique, could also be employed. In this technique, small dots of blue, green and red-sensitive emulsions have associated therewith, respectively, dots of yellow, magenta and cyan color-providing substances. After development, the transferred dyes would tend to fuse together into a continuous tone.

The photographic layers employed in the practice of this invention can contain surfactants such as saponin, anionic compounds such as the alkyl aryl sulfonates described in Baldsiefen U.S. Pat. 2,600,831; amphoteric compounds such as those described in Ben-Ezra U.S. Pat. 3,133,816; and water soluble adducts of glycidol and an alkyl phenol such as those described in Olin Mathieson British Pat. 1,022,878.

The various layers, including the photographic layers, employed in the practice of this invention can contain light absorbing materials and filter dyes such as those described in Sawdey U.S. Pat. 3,253,921; Gaspar U.S. Pat. 2,274,782; Silverstein et al. U.S. Pat. 2,527,583 and Van Campen U.S. Pat. 2,956,879. If desired, the dyes can be mordanted, for example, as described in Milton et al. U.S. Pat. 3,282,699.

The sensitizing dyes and other addenda used in the practice of this invention can be added from water solutions or suitable organic solvent solutions can be used. The compounds can be added using various procedures including those described in Collins et al. U.S. Pat. 2,912,- 343; McCrossen et al. U.,S. Pat. 3,342,605; Audran U.S. Pat. 2,996,287 and Johnson et al. U.S. Pat. 3,425,835.

The photographic layers used in the practice of this invention can be coated by various coating procedures including dip coating, air knife coating, curtain coating, or extrusion coating using hoppers of the type described in Beguin U.S. Pat. 2,681,294. If desired, two or more layers can be coated simultaneously by the procedures described in Russell U.S. Pat. 2,761,791 and Wynn British Pat. 837,- 095. This invention also can be used for silver halide layers coated by vacuum evaporation as described in British Pat. 968,453 and Lu Valle et al. U.S. Pat. 3,219,451.

The photographic and other hardenable layers used in the practice of this invention can be hardened by various organic or inorganic hardeners, alone or in combination, such as the aldehydes, and blocked aldehydes, ketones,

carboxylic and carbonic acid derivatives, sulfonated esters, sulfonyl halides and vinyl sulfonyl ethers, active halogen compounds, epoxy compounds, aziridines, active olefins, isocyanates, carbodiimides, and polymeric hardeners such as oxidized polysaccharides like dialdehyde starch and oxyguargum and the like.

The following examples further illustrate the invention:

EXAMPLE 1 A multilayer, multicolor photosensitive element is prepared by coating the following layers in the order recited on a cellulose acetate film support:

(1) Red-sensitive internal image gelatin-silver chlorobromide emulsion (171 mg. gelatin/ft. and mg. silver/ft. cyan image transfer coupler l-hydroxy-4-{4- [a (3 pentadecylphenoxy)butyramido] phenoxy} N- ethyl-3',5-dicarboxy-2-naphthanilide mg./ft. a development modifier 2-(2-octadecyl)-5-sulfohydroquinone potassium salt (1 mg./ft. and a fogging agent formyl-4- methylphenylhydrazine (0.5 mg./ft.

(2) An interlayer comprising I-hydrOXy-N-[a-(ZA-diter-amylphenoxy)butyl] -2-naphthamide (45 mg./ft. tricresyl phosphate 23 mg./ft. and gelatin 65 mg./ft.

(3) Green-sensitive internal image gelatin-silver chlorobromide emulsion (116 mg. gelatin/ft. and 100 mg. silver/ ft. magenta image transfer coupler 1phenyl-3(3,5-dicarboxyanilino) octadecylcarbamylphenylthio) -5 pyrazolone' (79 mg./ft. N-n-b utylacetanilide (40 mg./ft. a development modifier 2-(2-octadecyl)-5-sulfohydroquinone potassium salt (1 mg./ft. and a fogging agent formyl-4-methylphenylhydrazine (0.5 mg./ft.

(4) A yellow filter layer comprising l-hydroxy-N-[a- (2,4-ditert-amylphenoxy)butyl]-Z-naphthamide (50 mg./ ft. tri-cresyl phosphate (25 mg./ft. Carey Lea silver (15 mg./ft. and gelatin (65 mg./ft.

(5) Blue-sensitive internal image gelatin-silver chlorobromoiodide emulsion (126 mg. gelatin/ft. and 100 mg. silver/ft. yellow image transfer coupler a-pivalyl-a-(4- nitro-3 )-pentadecylphenoxy)-4-sulfamoylacetanilide 100 mg./ft. N-n-butylacetanilide (50 mg./ft. a development modifier 2-(2-octadecyl)-5-sulfohydroquinone potassium salt (1 mg./ft. and a fogging agent formyl-4-methylphnylhydrazine (0.5 mg./ft.

(6) Overcoat of gelatin (50 mg./ft. and l-hydroxy- N- [a- 2,4-di-tert-amylphenoxy) butyl] -2-naphthamide (20 mg./ft.

A multilayer dye image-receiving element is prepared by coating the following layers in the order recited on a polyethylene coated paper support:

(1) A pH lowering layer of poly(methylvinylether/ maleic anhydride) (750 mg./ft. and

(2) A dye image-receiving layer of copoly[styrene-N benzyl-N,N-dimethyl-N-( 3 maleimidopropyl)ammonium chloride] (700 mg./ft. The photosensitive element is exposed to a graduated-density multicolor test object. The following processing composition is spread from a pod between the exposed surface of the element and the superposed image-receiving element by passing the transfer sandwich between a pair of juxtaposed pressure rollers:

Benzyl alcohol: 10.0 ml.

Sodium hydroxide: 25.0 g.

4-amino-n-ethyl-N-p-hydroxyethyl anilino sulfate, free base: 30.0 g.

4-nitrobenzimidazole: 0.24 g.

Hydroxyethyl cellulose: 30.0 g.

Piperidinohexose reductone: 0.2 g.

Distilled water to total volume: 1 liter.

After 60 seconds at about 20 C., the dye image-receiving element is peeled apart from the negative. After three weeks keeping at approximately 22 C./50% R.I-I. under fluorescent room light conditions, the minimum densities to red, green and blue light are measured and recorded in Table I.

15 EXAMPLE 2 The procedure as described in Example 1 is followed with the exception that a hydrophilic colloidal overcoat layer of gelatin is provided over the dye image-receiving layer at a coverage of 36 mg./ft. The sensitometric results are listed in Table I.

EXAMPLE 3 The procedure as described in Example 2 is followed with the exception that a hydrophilic colloidal overcoat layer of casein is provided over the dye image-receiving layer at the same coverage.

The sensitometric results are listed in Table I.

TABLE I Dmin. Dmnx.

Dr; D D D DB 0. 26 O. 34 0. 66 0. 98 0. 87 0. 24 O. 28 1. 20 1. 43 1. 04 0. 25 0. 3O 1. 20 1. 35 1. 07

EXAMPLE 4 The procedure of Example 2 is repeated with the addition of 25 mg./ft. of the ultraviolet absorber 2(2-hydroxy-3,5-ditert amylphenol)benzotriazole in the overcoat layer. Similar results are obtained.

EXAMPLE The procedure of Example 2 is repeated except that 700 mg./ft. of copoly[styrene-N,N,N-trimethyl-N-(El-maleimidopropyl)ammonium p-toluenesulfonate] is employed as the dye image-receiving layer instead of copoly[styreneN-benzyl N, N-dimethyl-N-(3-maleimidropropyl) ammonium chloride]. Similar results are obtained.

The invention has been described with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be efiected within the spirit and scope of the invention.

I claim:

1. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising:

(a) a photosensitive element comprising a support having thereon at least one photosensitive silver halide emulsion layer, each said silver halide emulsion layer having associated therewith a non-difi'usible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a dilfusible dye;

(b) a dye image-receiving layer coated on a support and adapted to be superposed on said photosensitive element after exposure thereof; and

(c) a rupturable container containing an alkaline processing composition and Which is adapted to be positioned between said photosensitive element and said dye image-receiving layer during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the containers contents between the outermost layer of said photosensitive element and said dye image-receiving layer;

said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing a hydrophilic colloid layer over said dye image-receiving layer, said dye image-receiving layer comprising a basic polymeric mordant.

2. The photographic film unit of claim 1 wherein said photosensitive element comprises a support having thereon a red-sensitive silver halide emulsion layer having associated therewith a cyan dye image-providing material comprising a nonditfusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a ditfusible cyan dye, a green-sensitive silver halide emulsion layer having associated therewith a magenta dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye, and a blue-sensitive silver halide emulsion layer having associated therewith a yellow dye image-providing material comprising a nondiflusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diifusible yellow dye.

3. The photographic film unit of claim 1 including a pH-lowering layer between said dye image-receiving layer and its support.

4. The photographic film unit of claim 1 wherein said hydrophilic colloid layer is present at a coverage of 20- mg. per square foot.

5. The photographic film unit of claim 1 wherein said hydrophilic colloid layer comprises gelatin.

6. The photographic film unit of claim 1 wherein said hydrophilic colloid layer comprises casein.

7. The photographic film unit of claim 1 wherein said basic polymeric mordant comprises a polymer having at least /3 of the units represented by the following formula in copolymeriezd relationship with units of at least one other ethylenically unsaturated monomer:

Lapel L b-l n -i e-n x wherein R and R are hydrogen atoms or lower alkyl groups and R can additionally be a group containing at least one aromatic nucleus; Q can be a covalent bond, a divalent alkylene radical, a divalent arylene radical, a divalent aralkylene radical, a divalent arylenealkylene radical,

o -0 d-R wherein R is an alkylene radical, or R can be taken together with Q to form a R R and R can be lower alkyl or aryl groups, or R and R and the nitrogen atom to which they are attached can be taken together to represent the atoms and bonds necessary to form a quaternized nitrogen-containing heterocyclic ring which is attached to Q, and X is a monovalent negative salt-forming radical or atom; wherein said polymer is substantially free of carboxy groups. 8. The photographic film unit of claim 7 wherein said basic polymeric mordant is copoly[styrene-N-benzyl-N,N dimethyl-N-(3-rnaleimidopropyl)ammonium chloride.

9. The photographic film unit of claim 1 wherein said hydrophilic colloid layer contains an ultraviolet absorbing material.

10. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising:

(I) a photosensitive element comprising a support having thereon the following layers in sequence:

(a) a direct-positive, red-sensitve silver halide emulsion layer containing a nondilfusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye;

(b) an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent;

(c) a direct-positive, green-sensitive silver halide emulsion layer containnig a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a dilfusible magenta dye;

(d) an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent; and

(e) a direct-positive, blue-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diifusible yellow dye;

each said nondiffusible coupler having the formula:

DYELINK COUPBALL) n BALLLINK COUP-SOL wherein:

(l) DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

(3) COUP is a coupler radical selected from the group consisting of a S-pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said coupler non-diffusible during development in said alkaline processing composition;

(5) SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of 1 to 2 when said LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical;

(II) a dye image-receiving element comprising a support having thereon a polymeric acidic material layer and a dye image-receiving layer, said element being adapted to be superposed over said blue-sensitive silver .halide emulsion layer after exposure of said photosensitive element; and

(III) a rupturable container containing an alkaline processing composition and which is adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will efiect a discharge of the containers contents between said dye image-receiving layer and said blue-sensitive silver halide emulsion layer of said photosensitive element; said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing a hydrophilic colloid layer comprising gelatin over said dye image-receiving layer, said dye image-receiving layer comprising a basic olymeric mordant.

11. The photographic film unit of claim 10 wherein said basic polymeric mordant comprises a polymer having at least /3 of the units represented by the following formula in copolymerized relationship with units of at least one other ethylenically unsaturated monomer:

wherein R and R are hydrogen atoms or lower alkyl groups and R can additionally be a group containing at least one aromatic nucleus; Q can be a covalent bond, a divalent alkylene radical, a divalent arylene radical, a divlent aralkylene radical, a divalent arylenealkvlene radical wherein R is an alkylene radical, or R can be taken together with Q to form a -o II 0 group; R R and R can be lower alkyl or aryl groups, or R and R and the nitrogen atom to which they are attached can be taken together to represent the atoms and bonds necessary to form a quaternized nitrogen-containing heterocyclic ring which is attached to Q, and X is a monovalent negative salt-forming radical or atom; wherein said polymer is substantially free of carboxy groups and wherein the positive salt-forming radical of said polymer comprises at least two aryl groups for each quaternary nitrogen atom in said polymer and said gelatin layer is present at coverage of 20-100 mg. per square foot.

12. In a process of forming a transfer image comprising:

(a) imagewise-exposing a photosensitive element comprising a support having thereon at least one photosensitive silver halide emulsion layer, each said silver halide emulsion layer having associated therewith a nondiifusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a difiusible dye;

(b) superposing over the layer outermost from the support of said exposed photosensitive element a dye image-receiving layer coated on a support;

(c) positioning a rupturable container containing an alkaline processing composition comprising an aromatic primary amino color developing agent between said exposed photosensitive element and said dye image-receiving layer;

(d) applying a compressive force to said container to effect a discharge of the containers contents between said outermost layer of said exposed photosensitive element and said dye image-receiving layer;

(e) forming an imagewise distribution of diffusible dye image-providing material as a function of said imagewise exposure of each said silver halide emulsion layer; and

(f) at least a portion of each said imagewise distribution of diifusible dye image-providing material diffusing to said dye image-receiving layer;

the improvement comprising employing a hydrophilic colloid layer over said dye image-receiving layer, said dye image-receiving layer comprising a basic polymeric mordant.

13. The process of claim 12 wherein said photosensitive element comprises a support having thereon a red-sensitive silver halide emulsion layer having associated therewith a cyan dye image-providing material comprising a nondifiusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to pro duce a difiusible cyan dye, a green-sensitive silver halide emulsion layer having associated therewith a magenta dye image-providing material comprising a nondifiusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a ditfusible magenta dye, and a blue-sensitive silver halide emulsion layer having associated therewith a yellow dye imageproviding material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a ditfusible yellow dye.

14. The process of claim 12 including a pH-lowering layer between said dye image-receiving layer and its support.

15. The process of claim 12 wherein said hydrophilic colloid layer is present at a coverage of 20-100 mg per square foot.

16. The process of claim 12 wherein said hydrophilic colloid layer comprises gelatin.

17. The process of claim 12 wherein said hydrophilic colloid layer comprises casein.

18. The process of claim 12 wherein said basic polymeric m-ordan com-prises a polymer having at least /3 of the units represented by the following formula in copolymerized relationship with units of at least one other ethylenically unsaturated monomer:

wherein R and R are hydrogen atoms or lower alkyl groups and R can additionally be a group containing at least one aromatic nucleus: Q can be a covalent bond, a divalent alkylene radical, a divalent arylene radical, a divalent aralkylene radical, a divalent arylenealkylene radical,

or i

wherein R is an alkylene radical, or R can be taken together with Q to form a group; R R and R can be lower alkyl or aryl groups, or R and R and the nitrogen atom to which they are attached can be taken together to represent the atoms and bonds necessary to form a quaternized nitrogencontaining heterocyclic ring which is attached to Q, and X is a monovalent negative salt-forming radical or atom; wherein said polymer is substantially free of carboxy groups.

19. The process of claim 18 wherein said basic polymeric mordant is copoly [styrene-N-benzyl-N,N-dimethyl- N- 3-maleimidopropyl ammonium chloride.

20. The process of claim 12 wherein said hydrophilic colloid layer contains an ultraviolet absorbing material.

21. In a process of forming a transfer image comprismg:

(I) imagewise exposing a photosensitive element comprising a support having thereon:

(a) a direct-positive, red-sensitive silver halide emulsion layer containing a nondifiusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce -a diffusible cyan dye;

(b) an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent;

(c) a direct-positive, green-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diifusible magenta dye;

(d) an alkaline solution-permeable interlayer concontaining a compound capable of scavenging oxidized aromatic primary amino color developing agent; and

(e) a direct-positive, blue-sensitive silver halide emulsion layer containing a nondiifusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a dilfusible yellow dye;

each said nondiifusible coupler having the formula:

DYELINK-(COUPBALL) n BALLLINK-(COUPSOL) n (1) DYE is a dye radical exhibiting selective absorption in the visible spectrum and containing an acidic solubilizing group;

(2) LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;

(3) COUP is a coupler radical selected from the group consisting of a S-pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;

(4) BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said coupler non- 21 diffusible during development in said alkaline processing composition;

() SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

(6) n is an integer of 1 to 2 when said LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical;

(II) superposing over said blue-sensitive silver halide emulsion layer after exposure of said photosensitive element a dye image-receiving element comprising a support having thereon a polymeric acidic material layer and a dye image-receiving layer;

(III) positioning a rupturable container containing an alkaline processing composition comprising an aromatic primary amino color developing agent between said exposed photosensitive element and said dye image-receiving layer;

(IV) applying a compressive force to said container to efiect a discharge of the containers contents between said outermost layer of said exposed photosensitive element and said dye image-receiving layer;

(V) forming an imagewise distribution of dilfusible dye image-providing material as a function of said imagewise exposure of each said silver halide emulsion layer; and

(VI) at least a portion of each said imagewise distribution of diffusible dye image-providing material diffusing to said dye image-receiving layer;

the improvement comprising employing a hydrophilic colloid layer comprising gelatin over said dye image-receiving layer, said dye image-receiving layer comprising a basic polymeric mordant.

22. The process of claim 21 wherein said basic polymeric mordant comprises a polymer having at least /3 of the units represented by the following formula in copolymerized relationship with units of at least one other ethylenically unsaturated monomer:

Lari Li @J wherein R and R are hydrogen atoms or lower alkyl groups and R can additionally be a group containing at 22 least one aromatic nucleus; Q can be a covalent bond, a divalent alkylene radical, a divalent arylene radical, a divalent aralkylene radical, a divalent arylenealkylene radical,

O A l-wwherein R is an alkylene radical, or R can be taken together with Q to form a R R and R can be lower alkyl or aryl groups, or R and R and the nitrogen atom to which they are attached can be taken together to represent the atoms and bonds necessary to form a quaternized nitrogen-containing heterocyclic ring which is attached to Q, and X is a monovalent negative salt-forming radical or atom; wherein said polymer is substantially free of carboXy groups and wherein the positive salt-forming radical of said polymer comprises at least two aryl groups for each quaternary nitrogen atom in said polymer and said gelatin layer is present at a coverage of 20-100 mg. per square foot.

References Cited UNITED STATES PATENTS 3,227,550 1/1966 Whitmore et al. 963 2,839,401 6/1958 Gong et al. 9684 A 2,675,316 4/1954 Carroll et a1. 9684 A 2,661,293 12/1953 Land 96-3 X NORMAN G. TORCHIN, Primary Examiner A. T. SURO PICO, Assistant Examiner US. Cl. X.R.

9629 D, 76 C, 77, 84 A 

